Fall-winter habitat utilization of Eurasian Wigeon and American Wigeon with notes on migration and highly pathogenic avian influenza H5N1 virus

I studied fall and winter habitat utilization of Eurasian Wigeon (Anas penelope), and American Wigeon (Anas americana) using time budgets in the Sacramento Valley, California. Habitat utilization by American and Eurasian Wigeon differed only in the proportion of time spent in locomotion and vigilance. Resting, feeding, and locomotion were the top three behaviors exhibited by wigeon (American and Eurasian Wigeon collectively) during each month and in each pond. Increased feeding by wigeon from November through February suggested an increase in their energetic demands. Seasonally flooded wetlands were determined to be an important habitat for wigeon, as feeding and resting were the most common behaviors each month in these habitats. Asymmetric aggressive behavior patterns of Eurasian Wigeon toward American Wigeon suggested these wigeon species may be competing for resources. I studied the migration patterns of Eurasian Wigeon and their associations with Highly Pathogenic Avian Influenza Virus H5N1. One Eurasian Wigeon was equipped with a North Star solar-powered 16g platform transmitter terminal (PTT). I followed this bird’s two-day migration to Central Washington and, subsequently, its daily movements for the final six months of its life. Using a data base of all banded Eurasian Wigeon from 1929 to 2010, a map was constructed showing migration routes, stopovers, and a pattern of winter philopatry. In addition, oral and cloacal swabs of eight Eurasian Wigeon were taken, with negative results for H5N1.